1. Field of the Invention
The present invention relates to a bonding apparatus and more particularly to a bonding apparatus with a bonding tool cleaning mechanism.
2. Prior Art
Currently, grindstones and wire brushes are used as a bonding tool cleaning means in bonding apparatuses such as an inner lead bonding apparatus, outer lead bonding apparatus, transfer bump bonding apparatus, chip bonding apparatus, etc.
Grindstones are suitable for removing substances adhering to the undersurface of the bonding tool; however, they do not remove the substances, which ar on the side surfaces of the bonding tool, well. On the other hand, wire brushes remove the substances adhering to the side surfaces of the bonding tool very efficiently, and they can also remove the substances adhering lightly to the undersurface of the bonding tool. Accordingly, the undersurface of the bonding tool is cleaned first by the grindstones, and then the side surfaces and the undersurface of the bonding tool are further cleaned with wire brushes.
Examples of conventional bonding apparatuses that use wire brushes are disclosed in Japanese Patent Application Laid-Open ("Kokai") Nos. 60-246643 (called "Conventional Example 1") and No. 3-32041 (called "Conventional Example 2" which corresponds to the U.S. patent application No. 07/616,194).
In Conventional Example 1, a wire brush is provided on the outer surface of a cylindrical ring. The cylindrical ring is installed so that its axis is oriented horizontally, and bonding tool cleaning is performed by rotating the ring. In Conventional Example 2, a wire brush is installed on a cleaning stand, and bonding tool cleaning is done by moving the cleaning stand horizontally by an X-Y table.
More specifically, since in Conventional Example 1 the cylindrical ring is installed horizontally, the brush on the rotating cylindrical ring can clean only the side surfaces of the bonding tool. In other words, although two opposite side surfaces of the bonding tool can be cleaned by the wire brush rotating in the forward and reverse directions, the remaining two side surfaces of the bonding tool are not cleaned. Furthermore, the undersurface of the bonding tool is cleaned only in the direction of rotation of the wire brush, and no cleaning is performed in the direction perpendicular to the direction of rotation of the wire brush. Thus, cleaning efficiency is not very satisfactory.
In Conventional Example 2, the wire brush does not rotate. Instead, bonding tool cleaning is accomplished by moving the cleaning stand on a horizontal plane. Accordingly, only the undersurface of the bonding tool is cleaned, and the side surfaces are not cleaned well. Thus, complete cleaning cannot be accomplished, and the cleaning efficiency tends to be poor.